U.S. Pat. No. 5,630,402, granted May 20, 1997, to Michael J. Devine and Robert L. Kiliz, and assigned to Timing Systems, Inc., of Seattle, Wash., discloses and covers a fuel injection timing system that comprises an input drive member, an output drive member and an intermediate drive member. The output drive member is adapted to be rotatably coupled to a pump shaft of a fuel injection pump, to rotate the fuel injection pump shaft about its axis. The input drive member is adapted to be rotatably coupled to a drive source. The intermediate drive member is axially movable along an axis of the pump shaft between the input and output drive members. An actuator is provided that is movable along an axis that is perpendicular to the pump shaft axis. The actuator is coupled to the intermediate drive member and is adapted to move the intermediate drive member along the pump shaft axis. The intermediate drive member is coupled to the input drive member in a manner where axial movement of the intermediate drive member causes the intermediate drive member to rotate about the pump shaft axis. The intermediate drive member is coupled to the output drive member in a manner where movement of the intermediate drive member along the pump shaft axis causes rotational movement of the output drive member about the pump shaft axis. The actuator moves the intermediate drive member axially along the pump shaft axis to adjust the angular position of the output drive member relative to the input drive member.
The apparatus that is disclosed in U.S. Pat. No. 5,630,402 includes a pair of radially projecting pins on the intermediate drive member. The pins are positioned one hundred eighty degrees (180.degree.) apart on opposite sides of the intermediate drive member. The output drive member includes a pair of helical slots. The helical slots formed in the output drive member are also positioned one hundred eighty degrees (180.degree.) on opposite sides of the output drive member. Each helical slot is adapted to receive one of the pins and to cause is rotation of the output drive member in response to movement of the intermediate drive member axially along the pump shaft axis.
In such apparatus, the input drive member also includes a pair of helical slots, each adapted to receive a pin. The helical slots in the input drive member are curved in a direction opposite to that of the helical slots in the output drive member. As a result, linear movement of the intermediate drive member causes rotation of the intermediate drive member due to the pins engaging the helical slots in the input drive member.
The apparatus disclosed by U.S. Pat. No. 5,630,402 also includes a drive plate that is axially movable and includes a pair of radially projecting trunnions. It further includes a yoke having side members, each having an angled slot. The radially projecting trunnions on the drive plate are received within the angled slots. Movement of the yoke in a direction perpendicular to the pump shaft axis causes the. drive plate to move axially along the pump shaft axis. The drive plate is coupled to the intermediate drive member so that as it moves, it moves the intermediate drive member with it, along the pump shaft axis.
An object of the present invention is to provide new embodiments of the fuel injection timing apparatus that is disclosed in and covered by U.S. Pat. No. 5,630,402.
Another object of the present invention is to provide an improvement in the way in which the input drive member and the output drive member are coupled to the intermediate drive member.
A further object of the present invention is to provide an improved construction of the housing for the fuel injection timing system.
Yet another object of the present invention is to provide improvements in the way the yoke is driven and guided and variations in the way the fuel pump shaft is coupled to the output drive member.